Percutaneous transluminal septal myocardial ablation for hypertrophic obstructive cardiomyopathy in patients with situs inversus totalis: A two-case series.

UNLABELLED: Percutaneous transluminal septal myocardial ablation (PTSMA) is an established treatment for hypertrophic obstructive cardiomyopathy (HOCM), but its application in patients with situs inversus totalis (SIT) is complicated by mirror-image anatomy. We describe two successful PTSMA procedures in women, aged 82 and 69 years, with HOCM and coexisting SIT. The second patient had additional complexities, including Kartagener syndrome and chronic steroid therapy for rheumatoid arthritis. Both patients presented with severe, drug-refractory symptoms and significant left ventricular outflow tract (LVOT) pressure gradients. Guided by meticulous pre-procedural planning and multi-modality imaging, PTSMA was successfully performed, leading to a substantial reduction in LVOT gradients and marked symptomatic relief in both patients. The procedures were well-tolerated without major complications, demonstrating the feasibility of PTSMA despite advanced age, complex comorbidities, and profound anatomical variations. Our experience suggests that PTSMA is a viable, safe, and effective therapeutic option for HOCM in the rare and complex setting of SIT. LEARNING OBJECTIVE: 1.To recognize that percutaneous transluminal septal myocardial ablation (PTSMA) can be a feasible, safe, and effective septal reduction therapy for patients with hypertrophic obstructive cardiomyopathy and coexisting situs inversus totalis, leading to significant hemodynamic and clinical improvement.2.To understand that advanced age and comorbidities, such as chronic low-dose steroid use, are not absolute contraindications to PTSMA.3.To appreciate the critical importance of meticulous pre-procedural planning and multi-modality intraprocedural imaging to navigate mirror-image anatomy and ensure procedural success.